/****************************************************************************
 *
 * Copyright 2016 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 *
 ****************************************************************************/
/****************************************************************************
 * examples/kernel_sample/barrier.c
 *
 *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <stdio.h>
#include <unistd.h>
#include <pthread.h>

#include "kernel_sample.h"

/****************************************************************************
 * Definitions
 ****************************************************************************/

#define HALF_SECOND 500000L

/****************************************************************************
 * Private Data
 ****************************************************************************/

static pthread_barrier_t barrier;

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Name: barrier_func
 ****************************************************************************/

static void *barrier_func(void *parameter)
{
	int id = (int)parameter;
	int status;

	printf("barrier_func: Thread %d started\n",  id);
#ifndef CONFIG_DISABLE_SIGNALS
	usleep(HALF_SECOND);
#endif

	/* Wait at the barrier until all threads are synchronized. */

	printf("barrier_func: Thread %d calling pthread_barrier_wait()\n", id);
	FFLUSH();
	status = pthread_barrier_wait(&barrier);
	if (status == 0) {
		printf("barrier_func: Thread %d, back with status=0 (I am not special)\n", id);
	} else if (status == PTHREAD_BARRIER_SERIAL_THREAD) {
		printf("barrier_func: Thread %d, back with status=PTHREAD_BARRIER_SERIAL_THREAD (I AM SPECIAL)\n", id);
	} else {
		printf("barrier_func: ERROR thread %d could not get semaphore value\n", id);
	}
	FFLUSH();

#ifndef CONFIG_DISABLE_SIGNALS
	usleep(HALF_SECOND);
#endif
	printf("barrier_func: Thread %d done\n",  id);
	FFLUSH();
	return NULL;
}

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: barrier_test
 ****************************************************************************/

void barrier_test(void)
{
	pthread_t barrier_thread[CONFIG_EXAMPLES_KERNEL_SAMPLE_NBARRIER_THREADS];
	pthread_addr_t result;
	pthread_attr_t attr;
	pthread_barrierattr_t barrierattr;
	int status;
	int i;

	printf("barrier_test: Initializing barrier\n");

	status = pthread_barrierattr_init(&barrierattr);
	if (status != OK) {
		printf("barrier_test: pthread_barrierattr_init failed, status=%d\n", status);
	}

	status = pthread_barrier_init(&barrier, &barrierattr, CONFIG_EXAMPLES_KERNEL_SAMPLE_NBARRIER_THREADS);
	if (status != OK) {
		printf("barrier_test: pthread_barrierattr_init failed, status=%d\n", status);
	}

	/* Create the barrier */

	(void)pthread_barrierattr_init(&barrierattr);

	/* Start CONFIG_EXAMPLES_KERNEL_SAMPLE_NBARRIER_THREADS thread instances */

	status = pthread_attr_init(&attr);
	if (status != OK) {
		printf("barrier_test: pthread_attr_init failed, status=%d\n", status);
	}

	for (i = 0; i < CONFIG_EXAMPLES_KERNEL_SAMPLE_NBARRIER_THREADS; i++) {
		status = pthread_create(&barrier_thread[i], &attr, barrier_func, (pthread_addr_t)i);
		if (status != 0) {
			printf("barrier_test: Error in thread %d create, status=%d\n", i, status);
			printf("barrier_test: Test aborted with waiting threads\n");
			goto abort_test;
		} else {
			printf("barrier_test: Thread %d created\n", i);
		}
	}
	FFLUSH();

	/* Wait for all thread instances to complete */

	for (i = 0; i < CONFIG_EXAMPLES_KERNEL_SAMPLE_NBARRIER_THREADS; i++) {
		status = pthread_join(barrier_thread[i], &result);
		if (status != 0) {
			printf("barrier_test: Error in thread %d join, status=%d\n", i, status);
		} else {
			printf("barrier_test: Thread %d completed with result=%p\n", i, result);
		}
	}

	/* Destroy the barrier */

abort_test:
	status = pthread_barrier_destroy(&barrier);
	if (status != OK) {
		printf("barrier_test: pthread_barrier_destroy failed, status=%d\n", status);
	}

	status = pthread_barrierattr_destroy(&barrierattr);
	if (status != OK) {
		printf("barrier_test: pthread_barrierattr_destroy failed, status=%d\n", status);
	}
	FFLUSH();
}
